Simplify (-3x^2+6x-12)+(5x+9)

$(- 3 x^{2} + 6 x - 12) + (5 x + 9)$

Step 1

Remove parentheses.

$- 3 x^{2} + 6 x - 12 + 5 x + 9$

Step 2

Add $6 x$ and $5 x$ .

$- 3 x^{2} + 11 x - 12 + 9$

Step 3

Add $- 12$ and $9$ .

$- 3 x^{2} + 11 x - 3$